package com.twq.utils;

import java.io.InputStream;
import java.sql.*;
import java.util.Properties;

public class JdbcUtils {
    private  static  String driver = null;
    private  static  String url = null;
    private  static  String username = null;
    private  static  String password = null;

    static{
        try {
            InputStream in = JdbcUtils.class.getClassLoader().getResourceAsStream("db.properties");
            Properties properties = new Properties();
            properties.load(in);

            driver = properties.getProperty("driver");
            url = properties.getProperty("url");
            username = properties.getProperty("username");
            password = properties.getProperty("password");

            //1驱动只用加载一次
        }
        catch (Exception e){
            e.printStackTrace();
        }

    }

    //获取连接
    public static Connection getConnection() throws SQLException{
        return DriverManager.getConnection(url,username,password);
    }

    //释放资源
    public static void release(Connection conn, Statement st, ResultSet rs){
        try {
            if(rs != null)
                rs.close();
            if(st != null)
                st.close();
            if(conn != null)
                conn.close();
        }
        catch (SQLException e) {
            e.printStackTrace();
        }
    }
}
